Prince Valdemar of Denmark was a member of the Danish royal family. He was the third son and youngest child of Christian IX of Denmark and Louise of Hesse-Kassel. He had a lifelong naval career.

Maria Feodorovna, known before her marriage as Princess Dagmar of Denmark, was Empress of Russia from 1881 to 1894 as the wife of Emperor Alexander III. She was the fourth child and second daughter of Christian IX of Denmark and Louise of Hesse-Kassel. Maria’s eldest son, Nicholas, was the last Emperor of Russia, ruling from 1 November 1894 until his abdication on 15 March 1917. Maria lived for 10 years after Bolshevik functionaries killed Nicholas and his immediate family in 1918.